The present application is directed to tools that provide for moving a spindle in both advance and retract feed directions and specifically to tools with interchangeable gears to adjust a feed rate of the spindle.
Positive feed tools, such as but not limited to feed drills, are conventionally known for performing operations on workpieces formed of substances such as steel, aluminum, titanium, and composites. Positive feed tools include a tool feed mechanism that feeds a bit into a work piece. Conventional applications for positive feed tools include, among other applications, drilling holes in various parts of aircraft.
Positive feed tools generally include a motor that drives gears in a gear head to move a spindle. The various gears in the gear head are configured to control the feed rate of the spindle. The feed rate is set to suit different hole sizes in different materials. Prior tools have required the entire gear head to be disassembled and one or more of the gears to be replaced in order to change the feed rate. This is a cumbersome task that is timely and sometimes difficult to complete. Further, disassembly of the complete gear head can affect the overall life of the tool. Other designs have included additional gears in the gear head. However, the additional gears add weight, size, and complexity to the tool. Further, these gear heads are often more expensive.